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ContinuousWave: Small Boat Electrical
Rule Automatic Bilge Pump
|Author||Topic: Rule Automatic Bilge Pump|
posted 03-09-2013 03:15 PM ET (US)
Rule says their 500 GPH Fully Automatic unit "turns on and checks for water every 2-1/2 minutes," and "the pump runs for about one second" if it does not sense water. It seems like the cycling on and off would be annoying. Is it?
posted 03-09-2013 04:42 PM ET (US)
Hi Frontier--I have one of these in my Montauk. The only time I run it on auto is when I'm in my slip and away from the boat, typically. If I'm out in the boat and need to use it, I just use the "ON" position. That being said, it is not very loud at all, and really cannot be heard above the motor noise.
I'm a fan and would get it again.
posted 03-09-2013 05:30 PM ET (US)
I dunno. I had one of these, and found it annoying to have it turn on every two minutes, most of the time for no reason.
I went back to the low-tech float switch.
But I could see if there is some reason a float switch is impractical (lots of crud in the water can foul it), then the automatic unit is a better choice.
|L H G||
posted 03-09-2013 05:49 PM ET (US)
I also use this pump in my Montauk (and also 18, 19 & 21 Outrage models) the same way [DVollrath] does. Battery drain is insignificant during a two-week period and the installation is clean in the small Montauk sump. The only time I would install a conventional float switch is if the boat is possibly left unattended for months.
The smooth wall discharge tubing is bundled with the engine cables and other wiring, and uses a 90 degrere elbow at the transom for discharge.
In the photo, you can see how I did my wiring, which I highly recommend. As you know, in a Montauk, the wiring to the on-off override dash switch has to run in the tunnel. So, in the event of pump replacement need, to avoid having to pull wires in and out of the tunnel, and to avoid splice connections deep in the tunnel, I brought the [Ancor brand] cable all the way back to the pump, making the splice connections easily accessible, and cutting the pump leads very short.
http://smg.beta.photobucket.com/user/lgoltz/media/Montauk%2017/ Scan_Pic0008.jpg.html?sort=6&o=48#/user/lgoltz/media/Montauk%2017/ Scan_Pic0008.jpg.html?sort=6&o=48&_suid=136286813557407657236881177987
The plastic orange wire nuts make the twisted wire splices, and are then filled with clear Boat Life caulking. In spite of what others here will tell you, or make fun of this detail, *THEY ARE TOTALLY, RELIABLY WATERPROOF" even though this location can be constantly wet or even under water. The entire installation is under the sump cover and does not show. This wire nut splice detail, originally suggested to me by Clark Roberts, is simple, waterproof and totally reliable. In other Whalers, I have other similar connections in constantly wet locations, and no failures or wire corrosion in 12 years on one of them. One inch before the wire nut, put a snap tie around the wires, which keeps the wires from differential movement in the caulked cup of the nut.
posted 03-09-2013 07:52 PM ET (US)
I would never use "wire nuts" to make splices in a boat.
posted 03-09-2013 09:50 PM ET (US)
I actually just ordered a 1000 GPH Johnson Pump Ultima Bilge Pump for my Montauk: http://www.amazon.com/gp/product/B000RZR2QI/ ref=oh_details_o00_s00_i00?ie=UTF8&psc=1
I also considered a Rule-mate and Whale Supersub, these all have a field effect sensor for engaging rather than a cycling load system like the Rule automatic.
The Rule Mate has generally horrible reviews and the Whale supersub is almost unheard of. Johnson pumps seem to a have a good reputation and the dimensions should allow it to fit in the small bilge of the Montauk.
I am prompted get one after putting it off for some time after having my boat fill up with water last weekend from high winds and wave action. A bilge pump would have easily avoided the situation.
posted 03-10-2013 08:39 AM ET (US)
You might check with the American Boat and Yacht Council to see if their electrical recommendations for wiring boats includes using "wire nuts" filled with a sealant. A further problem with this baroque approach is the general tendency for many sealants to leach acetic acid. Acetic acid corrodes copper wire quite nicely.
If you don't have any plastic orange wire nuts handy, you can use the cap from a small tube of toothpaste. If the wires are not large enough to make a tight fit in the toothpaste tube cab, buy a KIT-KAT candy bar. Remove the foil wrapper from the candy bar. Discard the candy bar, but retain the foil wrapper. Tear off a strip of the foil wrapper and wrap the foil around the wires. This will increase their diameter.
If you have an older tube of toothpaste, the container is often a conductive metal. If you scrape off the painted label, you can use the foil to encase the copper wires, increasing their diameter enough to fit into the toothpaste tube cap. As a plus, you can use the toothpaste for a sealant, too. The gives an all-in-one solution without having to buy the KIT-KAT bar or use sealant.
If you do get a KIT-KAT bar, save the unused portion of the foil wrapper. If you have a blown fuse of about 30-Ampere rating, you can wrap one layer of a KIT-KAT candy bar foil wrapper around the glass envelope of the 3AG-type fuse. By carefully reinserting the fuse into the holder, you can make a darn good temporary fuse. Tests have shown that a KIT-KAT candy bar foil wrapper makes about a 30-Ampere fuse if only one layer is used.
As a general rule is is a very bad idea to make splices in electrical conductors which will be immersed in water at any time. The makers of the sump pumps are aware of this, and that is why they give you long leads on the pump: so you can run the leads from the pump upward, out of the sump area, into a dry area where you can make connection to them. This is what I recommend you do. Make the connection to the pump leads well above the level of the sump. Use the proper techniques. ANCOR--the same people that sell the wire that is also recommended above--make water-tight wire splices that contain an internal gel or wax and have heat-shrink tubing. This is a better method.
posted 03-10-2013 09:37 PM ET (US)
I came across a reprint of ABYC recommendations for boat wiring, which says, rather clearly and without much room for interpretation:
"Twist on connectors, i.e., wire nuts, shall not be used.” ABYC E-184.108.40.206.
Toothpaste tube caps are similarly prohibited, as they are twist-on devices, too.
The RULE pumps can be ordered in alternative models that include power leads that are six feet long. This is a good idea to get the splice out of the wet area.
posted 03-10-2013 09:39 PM ET (US)
Aside to jimh: KIT-KAT bars generally have plastic wrappers which work well as insulator in my experience. I usually use Hershey's Kisses wrappers as conductors and KIT-KAT wrappers to minimize corrosion and unwanted shorting of my Hershey's Kisses wrappers.
posted 03-10-2013 09:41 PM ET (US)
I hate progress! Thirty years ago when I used a KIT-KAT candy bar as a temporary fuse the wrapper was metallic foil with a nice gold tint. This is a good example of a general rule: don't take advice from really old people.
posted 03-11-2013 04:56 AM ET (US)
If much real metal were used in those wrappers these days, it would probably cost KIT-KAT millions a year.
Even if KIT-KAT is now likely a subsidiary of Yamaha, or General Motors, or something.
posted 03-11-2013 07:36 AM ET (US)
Regarding the battery drain from a device that turns itself on at a certain interval:
The device must be drawing power all the time in order to keep track of the time so it can turn itself on at certain intervals. This means the device has a continuous power drain whenever it is connected for the automatic mode of operation. The drain of the timer may be small, but there must be some power consumed in operating the part of the circuit that is the timer.
Regarding the notion that in two weeks of operation the automatic cycling will cause a drain on the battery that is "insignificant":
When the pump is activated at two-minute intervals, power is supplied to the motor in the pump. In the case of a particular model, say a RULE 1500, the motor current is specified as 4.8-Amperes. We can calculate the current drain in Ampere-hours over a two-week period as follows:
First we compute the drain of one cycle as 4.8-Ampere-seconds in Ampere-hours
4.8-Amperes-second/cycle x 1-minute/60-seconds x 1-hour/60-minutes = 1.33 x 10^-3 Ampere-Hours/cycle
Now we compute how often this will cycle on and off in two weeks time:
1-cycle/2-min x 60-minutes/1-hour x 24-hour/1-day x 7-days/1-week x 2-weeks = 10,080 cycles = 1.008 X 10^4
Now we compute the drain from those cycles:
1.33 x 10^-3 Ampere-hours/cycle x 1.008 X 10^4 cycles = 13.3-Ampere-hours
If we assume that a typical small boat like a Boston Whaler MONTAUK will have a battery whose capacity is 40-Ampere-hours, and if we leave the boat unattended with the RULE 1500 pump in the automatic mode, in a two week period the automatic operation of the pump will cause the battery to lose 13-Ampere-hours of charge. This is about 33-percent of its capacity. This is only the drain from the cycling of the pump motor. There is also a constant drain from the timer circuit, but we do not have any data on the amount of current.
posted 03-11-2013 08:00 AM ET (US)
Also, in my analysis above I have not considered that the pump might actually find some water to be pumped overboard. This will further drain the battery. So we can see that if at any time during the two weeks of automatic operation, the pump had to run for a few minutes to expel some water, the drain on the battery would increase more.
Let us say the boat has a little leak or there is some rain, and the pump has to run once an hour for one minute to expel the water. This is a drain of 0.08-Ampere-hour per cycle, and we have one cycle per hour, 24-cycles per day, for 14-days, or a total discharge of 27-Ampere-hours.
Now we add the drain from the automatic operation and the actual pumping, to find that in two weeks the pump will consume 27 + 13 Ampere-hours, or 40-Ampere-hours, which is the capacity of the battery.
We come back to the boat after two weeks and find the battery dead.
posted 03-11-2013 08:29 AM ET (US)
Re the notion that the float switch is "low tech":
In any system of control there will be a problem of the control system and its thresholds. There has to be some change in the threshold from the ON condition to the OFF condition compared to the threshold for the OFF condition to the ON condition. If there were not, the system would tend to chatter ON and OFF rapidly. In the case of a sump pump control system, we probably want the pump to go ON when the water rises in the sump above a certain level. Once the pump is on, we probably want it to pump out the water until the level falls below the threshold, and typically we want to pump the water until the level is well below the ON threshold. Imagine if the threshold were exactly the same. When the pump shuts off some water flows back from the pump chamber, filling the sump. This level exceeds the threshold. The pump comes back ON. This sort of control system leads to oscillation. To prevent the oscillation, we add some change in thresholds. This is called hysteresis.
The old-fashioned float switch actually adds hysteresis to the control loop through its design. The switch contains (in the old days) some liquid mercury, which is quite heavy. In the OFF condition, the mercury is pooled at the far end of the float lever. In order for the float to become buoyant, the water has to rise high enough to immerse most of the float. When the float become buoyant, the float lever rises, and the mercury drains out of the end of the lever toward the pivot point. There it completes the circuit and turns on the pump. Now that the mercury is pooled near the pivot point, the float is much more buoyant and it rides much higher in the water. This insures the pump is going to stay on for a while. As the pump runs, the water level drops, the lever moves downward, and the mercury begins to slowly move back toward the far end of the lever. At some point there is too much mercury at the far end and the buoyant force is over come. As soon this happens even more mercury flows into the far end of the lever, and the pump shuts off.
Because of the movement of the mercury, the float switch has a very advantageous control characteristic. The actual threshold for the ON or OFF decision is quite sensitive because it occurs when the float lever is nearly level and the mercury distribution is rather even. Once the threshold is crossed, the mercury flows either to the pivot or to the far end, immediately changing the threshold level so that an oscillation will not occur. This is really quite ingenious. I would not call it "low-tech" but rather high-tech, just not based on electronics.
In an electronic system the designer must provide some sort of hysteresis in the control system. This is usually done with an OFF-delay function, that is, there is a timer that makes the pump run for a certain amount of time after the threshold for OFF has been reached. This gives the pump a chance to expel more water. This insures that if the pump checks again in two minutes to see if there is water it is likely not to immediately come back on to expel the water it just left at the end of the last cycle.
posted 03-11-2013 08:33 AM ET (US)
To get back to the original question of the degree of annoyance from the pump cycling, I have to say that, if I were living aboard for two weeks, and if I heard the pump cycle on and off 10,000 times in those two weeks, I would likely find it annoying.
posted 03-11-2013 08:38 AM ET (US)
If installing a pump with a float switch for control, there are some other considerations to be handled. I describe these in an article in the REFERENCE section; see
posted 03-11-2013 10:28 AM ET (US)
Energy used to actually expel water is not relevant to a comparison of sensing technologies, as it is a function of pump design and all pumps of that design will pay that same penalty. Perhaps some pump designs may be more efficient at extracting water, but that would seem to be another thread.
I agree with Jim's analysis. I think it is wonderful we have all of these pump choices available to us.
If you are the live-aboard owner of a leaky boat who is easily annoyed, then perhaps an overcapacity cycling pump is not your best choice.
If you keep your Montauk in the water and install an appropriately sized pump, and patch the holes in the boat as diligently as you make your electrical connections, then you'll be fine with an auto-cycling pump for 4 weeks or more at a time (even if it rains).
If you trailer your boat, perhaps you don't need a pump at all.
posted 03-11-2013 12:15 PM ET (US)
I had this point of view until my boat filled up with water last weekend. Pulling the plug and getting on plane may not always be very feasible depending on situation and conditions.
I really wanted to go with a float switch over the cycling system not just for noise (which would be annoying) but also instance response. Once water gets in the boat I want it out now, the Rule automatics only check every few minutes from my understanding.
I went with the newer field effect sensor as most if pumps with built in switches are solid state now, the older rule mates had more standard internal float switches.
External float switches would be very difficult to fit in the small bilge on the Montauk.
posted 03-11-2013 01:11 PM ET (US)
I'm considering putting a 12 volt plug-in under the starboard-side gunwale over the sump and having an automatic bilge pump wired to a cigarette plug at the ready but stored in the console when not needed. The plug-in is a versatile power source for spot light, shrimp lights, 12v blender etc.
posted 03-11-2013 05:23 PM ET (US)
"It seems like the cycling on and off would be annoying. Is it?"
Yes, I have to shut off the power to it, when we are sleeping on board. It keeps me awake at night.
Whenever the engines are off you will notice it.
posted 03-13-2013 08:23 AM ET (US)
Although I mentioned fouling as one reason for not wanting a float switch, I do have to say that in 30 years, I've never had one foul despite various kinds of detrius accumulating in the bilge at various times. These have all been Rule pumps.
BTW, off-topic but I always found Rule pumps to be very reasonably priced, considering the sticker shock on many marine items.
posted 03-13-2013 09:36 AM ET (US)
I don't know the entire history of the RULE brand, but they probably were an independent manufacturing company at one point. They are now a brand of the Xylem company, which appears to be an offshoot made newly independent from ITT Corporation. The first sentence of the description for their RULE 1500 pump says, "High pumping capacity and reliability at a lower cost."
posted 03-13-2013 12:01 PM ET (US)
I just received my Johnson 1000 GPH automatic bilge pump, it looks like it will fit well in the small Montauk bilge. Here are some pictures of it, I will continue to add more as I install it:
posted 03-14-2013 08:20 AM ET (US)
I have two of these pumps, one on my 17 Outrage I, the other on my Tiara cruiser. Both boats were purchased used, with the pumps already installed. I find the cycling of the pump annoying, although when the engine is running the pump noise would be drowned out by motor noise. In the Tiara, the pump is installed in the cabin. We cruise that boat for several weeks every summer and that pump (there are three bilge pumps) is disengaged via a circuit breaker.
On the Outrage, the battery drain of the pump is not significant. The Outrage sits at a dock with a Mills mooring cover. This cover does allow some water intrusion via the cover cut-outs for the railing stanchions. The Outrage has sat unused for up to three weeks with the pump constantly cycling and the engine never fails to start easily. The battery is a typical Interstate deep cycle that was not new when I purchased the boat three years ago. Bob
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